1. Fields of the Invention
The invention relates to a drilling bit with the depth-limiting and angle-leading function for the carpenter's work, and more particularly, to a structure for adjusting the depth of the spot-faced hole in a workpiece (to be drilled).
2. Description of the Related Art
The drilling bit with the depth-limiting and angle-leading function is specifically employed for electric or pneumatic tools (not shown) for drilling a spot-faced hole in a workpiece. U.S. Pat. No. 7,258,513 teaches such a structure. In taking a closer look at the basic structure according to U.S. Pat. No. 7,258,513, it is found that a countersunk screw (fulfilling a specific clamping effect) has to be loosened when the length of the bit is re-adjusted for determining the depth of the spot-faced hole in a workpiece (after the drilling bit and the covering sleeve are attached to each other). After the adjustment, the countersunk screw has to be tightened back to its original position. The whole process is very complicated and takes up much time. Thus, the requirements of convenience and practicalness are not fulfilled. As a result, a further improvement is required.